timer.c File Reference

Timer, SysTick and timer-peripheral helpers for STM32F4 (Cortex-M4) More...

#include "core/cortex-m4/timer.h"
#include "core/cortex-m4/clock.h"
#include "core/cortex-m4/interrupt.h"
#include "core/cortex-m4/rcc_reg.h"
#include "core/cortex-m4/timer_reg.h"
#include "utils/timer_types.h"
#include <stdint.h>

Include dependency graph for timer.c:

Functions
<<<<<<< HEAD static volatile uint64_t systick_ticks=0;static volatile uint32_t tick_duration_us=1;static volatile uint32_t tick_reload_value=0;=======static volatile uint64_t systick_ticks=0;static volatile uint32_t tick_duration_us=1;static volatile uint32_t tick_reload_value=0;> > > > > > void	systick_init (uint32_t tick_us)
	Initialize the SysTick timer.
void	delay_us (uint64_t us)
	Busy-wait delay in microseconds.
void	delay_ms (uint32_t ms)
	Busy-wait delay in milliseconds.
uint64_t	hal_get_tick (void)
	Get current system tick count.
uint32_t	hal_get_tick_duration_us (void)
	Get configured tick duration.
uint32_t	hal_get_tick_reload_value (void)
	Get SysTick reload value.
uint32_t	hal_get_millis (void)
	Get system uptime in milliseconds.
uint32_t	hal_get_micros (void)
	Get system uptime in microseconds.
void	SysTick_Handler (void)
	SysTick interrupt handler.
void	timer_init (hal_timer_t timer, uint32_t prescaler, uint32_t auto_reload)
	Initialize timer based on type.

Detailed Description

Timer, SysTick and timer-peripheral helpers for STM32F4 (Cortex-M4)

This translation unit implements:

• SysTick initialization and microsecond tick counter
• Busy-wait delay helpers (delay_us, delay_ms)
• Timer peripheral base lookup, RCC enable, init/start/stop/reset
• Timer interrupt control, attach/detach callbacks and IRQ handlers
• Channel compare and PWM setup helpers

All logic uses direct register access matching the STM32F4 register layout.

Copyright

© NAVROBOTEC PVT. LTD.

Function Documentation

delay_ms()

void delay_ms

(

uint32_t

ms

)

Busy-wait delay in milliseconds.

Parameters

ms	Number of milliseconds to delay

delay_us()

void delay_us

(

uint64_t

us

)

Busy-wait delay in microseconds.

Parameters

us	Number of microseconds to delay

Note

Minimum delay is one tick period

hal_get_micros()

uint32_t hal_get_micros

(

void

)

Get system uptime in microseconds.

Returns

Microseconds since startup

hal_get_millis()

uint32_t hal_get_millis

(

void

)

Get system uptime in milliseconds.

Returns

Milliseconds since startup

hal_get_tick()

uint64_t hal_get_tick

(

void

)

Get current system tick count.

Returns

Current tick count

hal_get_tick_duration_us()

uint32_t hal_get_tick_duration_us

(

void

)

Get configured tick duration.

Returns

Tick duration in microseconds

hal_get_tick_reload_value()

uint32_t hal_get_tick_reload_value

(

void

)

Get SysTick reload value.

Returns

Current reload value (24-bit)

SysTick_Handler()

void SysTick_Handler

(

void

)

SysTick interrupt handler.

Increments the global tick counter

systick_init()

<<<<<<< HEAD static volatile uint64_t systick_ticks=0; static volatile uint32_t tick_duration_us=1; static volatile uint32_t tick_reload_value=0;======= static volatile uint64_t systick_ticks=0; static volatile uint32_t tick_duration_us=1; static volatile uint32_t tick_reload_value=0; > > > > > > void systick_init

(

uint32_t

tick_us

)

Initialize the SysTick timer.

Parameters

tick_us

Tick period in microseconds

Configures SysTick to:

• Use processor clock (AHB)
• Generate interrupts at specified interval
• Start counting immediately

  Note

  Reload value is limited to 24 bits

timer_init()

void timer_init	(	hal_timer_t	timer,
		uint32_t	prescaler,
		uint32_t	auto_reload )

Initialize timer based on type.

Parameters

timer	Timer identifier
prescaler	Prescaler value
auto_reload	Auto-reload value

Start timer counter

Parameters

timer

Timer identifier

Stop timer counter

Parameters

timer

Timer identifier

Set timer compare value for PWM

Parameters

timer	Timer identifier
channel	Channel number (1-4)
compare_value	CCR register value

Configures PWM mode 1 and enables the channel output

Enable timer channel output

Parameters

timer	Timer identifier
channel	Channel number (1-4)

Reset timer counter to zero.

Parameters

timer

Timer identifier.

Get the current counter value for a timer.

Parameters

timer

Timer identifier.

Returns

Current counter value or 0 if invalid timer.

Calculate the timer's current base frequency using PSC and ARR.

Parameters

timer

Timer identifier.

Returns

Timer frequency in Hz or 0 if invalid timer.

Note

This reads PSC and ARR directly from timer registers and uses the appropriate APB clock for the timer.

IRQ handler wrapper for TIM2.

Clears the flag and dispatches to the HAL interrupt handler table.

IRQ handler wrapper for TIM3.

IRQ handler wrapper for TIM4.

IRQ handler wrapper for TIM5.

IRQ handler for TIM1 BRK and TIM9 shared vector.

Note

This function clears TIM9's flag and dispatches using the shared IRQn.

Enable timer interrupts (NVIC + DIER UIE) for supported timers.

Parameters

timer

Timer identifier.

Note

For TIM1 more complex options exist and are left TODO in the original.

Attach a callback to the timer's HAL interrupt table.

Parameters

timer	Timer identifier.
callback	Function pointer to call when the timer IRQ fires.

Detach a previously attached callback for the given timer.

Parameters

timer

Timer identifier.

Set the compare (CCR) register for a timer channel and configure CCMR.

Parameters

timer	Timer identifier.
channel	Channel number (1-4).
compare_value	Value to write into CCRx.

Note

This function sets PWM mode 1 and enables the channel after writing CCR.

Disable timer channel output

Parameters

timer	Timer identifier
channel	Channel number (1-4)